Composite lumber



B. c. ROCKWEL'L, COMPOSITE LUMBEB.

APPLICATION FILED FEB. 5, 1920.

Panted- Mar. 14, 1922.

l lll UNITED STATES BYRD C. ROCKWELL, 0F CAMDEN, ARKANSAS.

COMPOSITE LUMBER.

Specification of Letters Patent.

Patented Mar. 14, 1922.

Application filed February 5, 1920.` Serial No. 356,426.

T o all-whom it may concern Be it known that I, BYRD C. RocKwELL', acitizen of the United States, residing at Camden, Arkansas, haveinvented a certain new and useful Improvement in Composite Lumber, ofwhich the following is a full, clear, and exact description such as-will enable others skilled in the art to which it appertains to makeand use the same, reference being had to the accompanying drawings,forming part of this specification.

My invention relates to composite lumber, the principal object of myinvention being to produce by a relatively simple, economical and easilypracticed method, lumber of the particular class that is generally usedfor finishing the interior of buildings andv for trimming door andwindow openings.

vIt is to a large extent the present practice to use high giade hardwoodlumber for finishing and trimming the interior of buildings and as thereis a growing scarcity of the desired kindsand grades of lumber, the costof finishing stock to the consumer is relativelyY high.

The greater portion of lumber used for interior trim and finish requiresone clear face and one clear edge, and I propose to produce satisfactoryfinishing lumber by combining a section of high grade straightgrainedstock with acore or backing strip of low grade or soft lumber, and asthe latter is concealed when the completed stock is applied for use, itcan be made up from any low grade and consequently inexpensive stock. A

By way of illustration, it may be stated that by practicing myinvention, I am able to combine one hundred dollars ($100.00) worth ofhigh grade 'finishing lumber with ten dollars ($10.00) worth of' lowgrade core and produce an amount of high grade finishing stock which forall practical purposes is in every way equal to two hundred dollars($200.00) worth of high grade finishing lumber, such increase beingaccomplished with a relatively small expense for labor and glue.

My invention contemplatesthe formation of similar strips or pieces fromhigh grade finishing material and inexpensive low grade material, andthe combining and uniting of two stripsof different materials throughthe use of a suitable adhesive such as the well-known weather-proof gluenow in general use, the dividing line or joint between Figure 2 is aperspective view of a short l section of low grade or inexpensive lumberutilizedin carrying outl my invention.

Figure 3 is a perspective view of a short section of the high gradestock after the same hasbeen cut and ready to be assembled with thelowgrade or inexpensive stock.

Figure 4 is a perspective view of a short section of the low grade orinexpensive stock, the same being cut and formed so asto -be applied tothe high grade stock.

Figure 5 is a perspective view of a short section of finishing lumberconstructed in y accordance with my invention'.

Figure 6 is a perspective view similar to Figure 5 and showing thecombined stock moulded along the corner of the high grade. material.

In the production of finishing lumber by my improved method, a piece ofstraight grai'ned high grade finishing lumber, as illustrated in Figure1, is divided lengthwise along the diagonally disposed line A, therebyforming two strips of uniform size and each strip being substantiallytriangular in cross section. f

Apiece of inexpensive lowl grade lumber that has the same width andthickness as the high grade material is divided' lengthwise alo'ng thedotted line B, Figure 2, thereby producing a pair of strips .of lowgrade material which are of equal s ize and eachpiece substantiallytriangular in cross section.

EaclL triangular strip of high grade material and which may bedesignated by the numeral 10 isA now provided on its inner or inclinedface with a longitudinally disposed groove or channel 10a, and thecorners of the material at the edges of this groove or channel areslightly rounded or beveled as designated by 12. (See Fig. 3), Likewisethe in bringing these glue coated faces together, .a tongue strip 15,preferably of wood, is

positioned in the coinciding grooves or channels 10a and 13. This tonguestrip is utilized for the purpose of preventing the pieces 10 and 11from slipping one upon the other when the glue coated faces are broughttogether and While the .pieces are being pressed together during thedrying period. This tongue strip is preferably square incross sectionand it may extend the entire length of the completed piece of materialor a number of short sections may be utilized and arranged at suitabledistances apart The rounded or vbeveled corners of the grooves orchannels in the pieces 10 and 11 enable the tongue strips to be readilypositioned in the grooves While the parts of the completed stock arebeing assembled. Thus when the pieces of high grade and low gradematerials have been properly assembled and the glue or adhesive hasthoroughly dried, a piece of finishing lumber such as is illustrated inFigure 5 is produced, 'and the section of high grade material isarranged in said piece so as to produce one clear edge and one clearface. These clear faces are disposed at right angles to each other andthe corner between said faces can be moulded in any desired shape, asillustrated in Figure 6, thereby forming ornamental finishing lumbersuch as is ordinarily used for baseboards, Wall finishing strips, andthe like.

Lumber manufactured in accordance with my invention does not present anexposed glue line on its face or edge, and for this reason the finishedstock can be readily moulded Without danger of injury or rapid wear tothe moulding bits.

By combining differently graded strips of the same wood, a finishedpiece of stock may be produced that has two clear edges and one clearface, but in following this practice, the core or backing strip must beformed from lumber which is graded to present one clear edge.

lVhile I have shown the grooves or 'channels 10a and 13 as being locatedat points approximately halfway between the edges of the strips in whichthey are formed, it will be understood that the location of said groovesmay vary as desired, and where they might interfere with the relativelydeep moulded cut along the central portion of the face of the stock. itis, of course, desirable to form the grooves adjacent to the Wider edgeof the high grade material and adjacent to the narrow edge of thelowgrade material or backing strip.

IVhile in the foregoing description I have referred to the lumberproduced by my improved methods as being particularly applicable forinterior finishing and trimming purposes, it will be understood thatlumber produced in accordance with my invention can be advantageouslyused wherever high grade wood finished surfaces are desired.

y improved method .may be easily practiced and one of the particularadvantageous results attained through its use is the economicalproduction of high grade finishing material. f

I claim: Y

l. A rectangular finishing strip comprising a substantially triangularstrip of one grade of material. a second substantially triangular stripof another and different grade of material, and means interposed betweenthe contiguous inclined faces of said strips for gether.

2. A rectangular finishing strip comprising a substantially triangularstrip of one grade of material, a second substantially triangular stripof another and different grade permanently securing them to- 4 ofmaterial, and medially arranged anchor-y ing means interposed betweenthecontiguous inclined faces of said strips for permanently securing themtogether.

In testimony whereof I hereunto affix my signature this 2nd day ofFebruary, 1920. BYRD C. ROCK WELL.

